Software Engineer

As a Software Engineer at Xsolla, you will own features end to end across backend, frontend, and smart contracts for Xsolla ZK, a Web3 ecosystem built on zkSync. You will work on smart wallets using account abstraction, SDKs for game studios, infrastructure services for tokenizing in-game assets, and ecosystem dApps including a DEX, NFT marketplace, and auction platform.

What you'll do

• Build backend services in Go and TypeScript for chain indexing, transaction relaying, event processing, and APIs for dApps and SDKs
• Build infrastructure backend services for tokenizing in-game items and currencies
• Build dApp frontends in React, handling wallet connection, transaction signing, and on-chain state in the UI
• Integrate smart wallets into products, working with accounts, paymasters, and bundlers
• Develop SDKs used by game studios and partners
• Design the on-chain and off-chain architecture of your product: decide what lives in contracts versus services and how they stay consistent
• Ensure security and correctness of what you ship, including signing flows and interactions with contracts that hold user assets, keys, and secrets
• Monitor services and contracts in production and take part in on-call rotation
• Review code from teammates
• Set up and maintain AI tooling in repositories (Claude Code, Codex, Cursor) so the team uses it effectively

What you bring

• 5+ years of commercial software development with senior-level production experience across backend and frontend
• Shipped dApps to production and maintained them
• Production experience with viem and wagmi: clients and transports, contract reads and writes with typed ABIs, event subscriptions, wagmi hooks and connectors, caching and invalidation of on-chain state
• Understanding of how wallet signers work: EOAs, browser and embedded wallets, smart accounts; personal_sign (EIP-191) and typed data (EIP-712); the EIP-1193 provider; network switching
• Hands-on experience with smart wallets: UserOperations, gas sponsored via paymasters, signature validation for contract accounts (ERC-1271)
• Production experience with Go and TypeScript (Node.js) for backend services
• Experience processing on-chain events: idempotency, reorg handling, retries
• Experience with asynchronous messaging and event-driven design (Kafka, RabbitMQ, or NATS): delivery guarantees, ordering, reprocessing
• Experience with relational databases (PostgreSQL) and caching (Redis)
• Ability to design REST and gRPC APIs: versioning, backward compatibility
• Strong React and TypeScript skills: rendering model, state management, performance
• Web security fundamentals: XSS, CSRF, CSP, safe handling of signatures and keys in the browser
• Ability to read and understand Solidity contracts and the EVM (storage, gas, call semantics, proxy upgrade patterns, access control) well enough to integrate safely and review changes
• Knowledge of common contract vulnerability classes (reentrancy, front-running/MEV, oracle manipulation, signature replay) and their off-chain implications
• Experience with containers and orchestration (Docker, Kubernetes) at the level of deploying and debugging your own services
• Experience with observability tools (Datadog, Prometheus, Grafana, ELK, Graylog, or OpenTelemetry): metrics, logs, tracing, alerting, and diagnosing production incidents
• Testing practices: unit, integration, and E2E
• Experience with Git and CI/CD (GitLab CI or similar)
• Daily hands-on use of AI coding tools (Claude Code, Codex, Cursor) for development and review, including configuring them for a repository
• Spoken English at B2 level or higher

Nice to have

• Experience with zkSync, ZK Stack, and zk-rollup specifics
• Experience designing, writing, and testing smart contracts in Solidity with Foundry; deploying and upgrading them safely
• Experience building ERC-4337 infrastructure (bundlers, paymasters); familiarity with EIP-6963 and EIP-5792
• DeFi experience: DEX and AMM mechanics
• NFT and marketplace experience: ERC-721, ERC-1155, auction mechanics
• L2 infrastructure experience: running nodes, indexers, bridges
• Experience designing SDKs for external developers
• Gaming domain experience

What we offer

• Remote work worldwide
• Full-time employment agreement (entity or EOR arranged per candidate location)
• Flexible schedule (10:00-19:00)
• Medical, dental, and vision coverage
• Paid time off
• Personalized career roadmap and professional development through training and educational opportunities

About Xsolla

Xsolla is a global video game commerce company headquartered in Los Angeles. It helps developers from indie to AAA fund, distribute, market, and monetize their games, serving as merchant of record for 1,500+ developers worldwide.